02-10-2012, 05:35 PM
Enterprise JavaBeans Fundamentals
Enterprise JavaBeans.ppt (Size: 1.17 MB / Downloads: 300)
What is Enterprise JavaBeans
The Enterprise JavaBeans architecture is a component architecture for the development and deployment of object-oriented distributed enterprise-level applications. Applications written using the Enterprise JavaBeans architecture is scalable, transactional and multi-user secure. These applications may be written once, and deployed on any server platform that supports the Enterprise JavaBeans specification
Sun Microsystems Enterprise JavaBeans™ Specification, v1.1, Copyright 1999 by Sun Microsystems, Inc.
Enterprise JavaBeans
Simple Programming Model
Attribute based programming
Focus on Business Logic
Simple API
Well defined Lifecycle
Portable
Specification ensures basic services
Component Packaging (JARs and XML DD)
Java
EJB Advantages
With EJB, you can write a business object and easily make it
Persistent
Distributed
Transactional
Secure
Multithreaded
Persistent
Beans need to load and store data
You can let the server do it
(Container-Managed Persistence)
You can do it yourself
(Bean-Managed Persistence)
Transactional
Support for distributed transactions
You can let the Server manage all transactions
You will if you know what’s good for you
You can give it hints in deployment descriptor
What’s in a name?
Enterprise Java Beans has absolutely nothing to do with JavaBeans
Except that both are Java-based component architectures
EJB is server-side, JB is client-side
EJB has no GUI, JB usually has GUI
JB is basically naming conventions for fully powered Java classes
EJB rules are much more rigid
EJB classes are less powerful on their own, but more powerful in a container